Request for shared Microscale Thermophoresis (MST) instrument Many fundamentally important biological processes are regulated by molecular interactions; gaining a deep understanding of biologically relevant interactions (e.g. RNA-protein, protein-protein, or receptor-ligand) serves as a foundation for understanding molecular mechanisms that underlie biological processes. Whereas an array of techniques are available to analyze biomolecular interactions, existing technologies, while effective, remain limited in some important ways. For example, although many essential biological functions are carried out by large, multi-subunit complexes, these generally cannot be studied with existing techniques because the amount of sample required is prohibitive. Similarly, the amount of sample and time required for completing a series of assays with sets of mutants is a common obstacle with current approaches. The Microscale Thermophoresis (MST) instrument requested here overcomes these and other limitations and will significantly expand the research capabilities of a large user base at UC-Boulder. Consider the following: * MST is not limited by size restrictions and measurements can be made in most any buffer, allowing analysis of most any biologically or biomedically relevant interaction, including small molecule binding to proteins, DNA and RNA; protein-protein, protein oligonucleotide or oligonucleotide-oligonucleotide interactions; interactions involving membrane binding proteins and more. * Because MST is performed free in solution without any surface immobilization, bulky or otherwise sensitive molecular assemblies such as liposomes or membrane proteins can be more easily investigated. * Thermophoresis is sensitive to changes in hydration shell; therefore, binding events can be detected even without an increase in size or mass upon complex formation. This can be especially important for investigation of small molecule binding interactions, such as enzyme-inhibitor or ligand-receptor interactions. * Experiment time and/or the amount of sample needed per experiment are considerably lower (orders of magnitude in some cases) than for alternative methods such as ITC, SPR, fluorescence polarization or EMSA. As a result, MST is rapidly becoming a workhorse technique for the fast characterization of biomolecular interactions. As one example, to investigate a 1:1 binding reaction with a Kd of 1 M, our ITC200 instrument would require 10 nanomoles of one binding partner and 20 micromoles of the other. By contrast, MST would require 3.2 picomoles and 500 picomoles, respectively. Many investigators at UC-Boulder and elsewhere are studying larger and more complex protein and nucleoprotein assemblies, which are difficult to isolate in large quantities. The MST technology opens up an array of experimental possibilities that simply are not feasible with existing instrumentation.